RPY2 RuntimeError: "There is no R_HOME environment variable calling the" R ROME "command that returns anything ..."

Question

I am running Python 2.7 on Windows 7. First I installed R and RTools and changed the following environment variables:

RHOME: C:\Program Files\R\R-2.15.2
R_HOME: C:\Program Files\R\R-2.15.2
R_USER: C:\Users\username\Documents

And added the following directories to PATH:

C:\Program Files\R\R-2.15.\bin\i386; C:\Rtools\bin

Then I installed RPy2 through the binary executable here.

When running RPY2 through Python, I get the following error:

Traceback (most recent call last):
  File "<string>", line 254, in run_nodebug
  File "C:\Python27\blaise automation.py", line 14, in <module>
    import rpy2.robjects as robjects
  File "C:\Python27\lib\site-packages\rpy2\robjects\__init__.py", line 14, in <module>
    import rpy2.rinterface as rinterface
  File "C:\Python27\lib\site-packages\rpy2\rinterface\__init__.py", line 28, in <module>
    "or install the win32 package.")
RuntimeError: No environment variable R_HOME could be found, calling the command 'R RHOME' does not return anything, and unable to import win32api or win32con, both of which being needed to retrieve where is R from the registry. You should either specify R_HOME or install the win32 package.

I am working on it for CLOCK. Does anyone know how to solve it?

My code is:

import rpy2.robjects as robjects
import pywin

def main():
     robjects.r("require(foreign)")